Category:TP3
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|style="background-color:#dfd"| PLANTS | |style="background-color:#dfd"| PLANTS | ||
|- | |- | ||
− | |colspan=" | + | |colspan="7"| 2,3-oxidosqualene |
|- | |- | ||
− | |colspan=" | + | |colspan="7"|[[Image:2,3-oxidosqualene.png]] |
|- | |- | ||
− | | lanosterol [[Image:Arrow00dl35.png]] synthase<ref>The most accessible enzyme among oxidosqualene cyclases.<br/>''Ref.'' Corey EJ, Russey WE, Ortiz-de-Montellano PR (1966) 2,3-Oxidosqualene, an intermediate in the biological synthesis of sterols from squalene ''J Am Chem Soc'' 88:4750-1</ref> | + | |colspan="4"| lanosterol [[Image:Arrow00dl35.png]] synthase<ref>The most accessible enzyme among oxidosqualene cyclases.<br/>''Ref.'' Corey EJ, Russey WE, Ortiz-de-Montellano PR (1966) 2,3-Oxidosqualene, an intermediate in the biological synthesis of sterols from squalene ''J Am Chem Soc'' 88:4750-1</ref> |
| lupeol [[Image:Arrow00dr35.png]] synthase | | lupeol [[Image:Arrow00dr35.png]] synthase | ||
|- | |- | ||
Line 80: | Line 80: | ||
''Ref.'' Corey EJ, Virgil SC (1991) An experimental demonstration of the stereochemistry of enzymic cyclization of 2,3-oxidosqualene to the protosterol system, forerunner of lanosterol and cholesterol. [http://pubs.acs.org/doi/abs/10.1021/ja00010a073 ''J Am Chem Soc'' 113:4025-6]</ref> | ''Ref.'' Corey EJ, Virgil SC (1991) An experimental demonstration of the stereochemistry of enzymic cyclization of 2,3-oxidosqualene to the protosterol system, forerunner of lanosterol and cholesterol. [http://pubs.acs.org/doi/abs/10.1021/ja00010a073 ''J Am Chem Soc'' 113:4025-6]</ref> | ||
<br/>[[Image:Protosteryl cation.png]] | <br/>[[Image:Protosteryl cation.png]] | ||
+ | |rowspan="2"| D-ring<br/>expansion<br/>[[Image:Arrow00r35.png]]<br/>+ E-ring<br/>cyclization<br/>(from 18α/17β) | ||
+ | |rowspan="2"| hancolupyl cation<br/>[[Image:Hancolupyl cation.png|150px]]<br/>arborinyl cation<br/>[[Image:Arborinyl cation.png|150px]] | ||
+ | | | ||
| 17β-dammarenyl cation<ref>The rings of dammarenyl cation are all-chair configuration. The C-17 chain is β-configuration.<br/> | | 17β-dammarenyl cation<ref>The rings of dammarenyl cation are all-chair configuration. The C-17 chain is β-configuration.<br/> | ||
''Ref.'' Xiong Q, Rocco F, Wilson WK, Xu R, Ceruti M, Matsuda SPT (2005) Structure and reactivity of the dammarenyl cation: configuration transmission in triterpene synthesis. ''J Org. Chem. 70:5362-75</ref> | ''Ref.'' Xiong Q, Rocco F, Wilson WK, Xu R, Ceruti M, Matsuda SPT (2005) Structure and reactivity of the dammarenyl cation: configuration transmission in triterpene synthesis. ''J Org. Chem. 70:5362-75</ref> | ||
<br/>[[Image:Dammarenyl cation.png]] | <br/>[[Image:Dammarenyl cation.png]] | ||
+ | | D-ring<br/>[[Image:Arrow00r35.png]]<br/>expansion | ||
+ | | baccarenyl cation<br/>[[Image:Baccarenyl cation.png]] | ||
|- | |- | ||
|align="center"| | |align="center"| | ||
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|- valign="top" | |- valign="top" | ||
| 1,2-[[Image:Arrow00d.png]] shift | | 1,2-[[Image:Arrow00d.png]] shift | ||
− | | [[Image:Arrow00dr35.png]] | + | | [[Image:Arrow00dr35.png]]<br/>protostane |
− | | | + | |} |
+ | | | ||
+ | |align="right"| | ||
+ | {| | ||
+ | | E-ring expansion<br/>(from 18α) | ||
+ | | [[Image:Arrow00dl.png]] | ||
+ | |} | ||
+ | |colspan="2"| | ||
+ | {| | ||
+ | | [[Image:Arrow00dl35.png]]<br/>baccharane<br/>etc. | ||
+ | |E-ring<br/> | ||
+ | |[[Image:Arrow00d.png]] | ||
+ | |expansion<br/>(from 18β) | ||
|} | |} | ||
− | |||
|- | |- | ||
| lanosteryl cation<br/>[[Image:Lanosteryl cation.png]] | | lanosteryl cation<br/>[[Image:Lanosteryl cation.png]] | ||
− | | | + | | |
+ | | | ||
+ | | | ||
+ | | H18β-lupyl cation<br/>[[Image:Lupyl cation2.png]] | ||
+ | | | ||
+ | | H18α-lupyl cation<br/>[[Image:Lupyl cation.png]] | ||
|- | |- | ||
|align="center"| | |align="center"| | ||
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|style="background-color:#fdd"| lanostane<br/>cycloartane<br/>all steroids | |style="background-color:#fdd"| lanostane<br/>cycloartane<br/>all steroids | ||
|} | |} | ||
− | | | + | | |
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
+ | | | ||
|- | |- | ||
| cucurbitenyl cation<br/>[[Image:Cucurbitenyl cation.png]] | | cucurbitenyl cation<br/>[[Image:Cucurbitenyl cation.png]] | ||
+ | | | ||
+ | | | ||
+ | | | ||
|style="background-color:#dfd"| lupeol<br/>[[Image:Lupeol.png]] | |style="background-color:#dfd"| lupeol<br/>[[Image:Lupeol.png]] | ||
+ | | | ||
+ | | | ||
|- | |- | ||
|style="background-color:#fdd"| Examples.<br/>All steroids including steroidal saponins | |style="background-color:#fdd"| Examples.<br/>All steroids including steroidal saponins | ||
+ | | | ||
+ | | | ||
+ | | | ||
|style="background-color:#dfd"| Examples.<br/>all triterpenoids and saponins | |style="background-color:#dfd"| Examples.<br/>all triterpenoids and saponins | ||
+ | | | ||
+ | | | ||
|} | |} | ||
</center> | </center> |
Revision as of 03:30, 9 August 2010
Contents |
Triterpene (C30) Classes
Ring configuration
The basic structure is 4 carbon rings, cyclopenta[a]phenanthrene, gonane, or sterane. The rings B/C are always trans in all natural steroids. If the rings C/D are trans, it is called gonane. If its stereochemistry is unspecified, it is called sterane. Most steroids take gonane form, but in cardenolides and bufanolides, the rings C/D are cis.
Cyclopenta[a]phenanthrene | Gonane |
The majority of steroids have methyl groups sticking out from the bridgehead positions C-10 and C-13. When these methyl groups (or hydrogens) stand above the plane, they are called β-configuration. Those below the plane are called α-configuration. If the configuration at any site is unknown, it is indicated as ξ (Greek Xi). By default, hydrogen atoms or substituents at the positions C-8, 9, 10, 13, and 14 are assumed to be 8β, 9α, 10β, 13β, and 14α configurations. C-5 is a special position, because there are as many 5α steroids as 5β are.
cholestane backbone | 5α-configuration | 5β-configuration |
Biosynthesis
The starting point is squalene, which is formed by joining two FPPs tail-to-tail. Bacterial cyclases use squalene directly, but those of the other species use 2,3-oxidosqualene for cyclization.
- In bacteria, squalene is cyclized via the 17α-deoxydammarenyl cation to hopene and other triterpenes[1].
- In eukaryotes, 2,3-oxidosqualene is cyclized via the protosteryl cation to lanosterol (animals and fungi) or cycloartenol (plants) by a series of 1,2-hydride and methyl shifts (Wagner-Meerwein shifts).[2]
- In plants, various triterpenes arise from the dammarenyl cation.
ANIMALS, FUNGI, and YEAST | PLANTS | |||||||||||
2,3-oxidosqualene | ||||||||||||
lanosterol synthase[3] | lupeol synthase | |||||||||||
17β-protosteryl cation[4] | D-ring expansion + E-ring cyclization (from 18α/17β) |
hancolupyl cation arborinyl cation |
17β-dammarenyl cation[5] | D-ring expansion |
baccarenyl cation | |||||||
|
|
| ||||||||||
lanosteryl cation |
H18β-lupyl cation |
H18α-lupyl cation | ||||||||||
|
||||||||||||
cucurbitenyl cation |
lupeol |
|||||||||||
Examples. All steroids including steroidal saponins |
Examples. all triterpenoids and saponins |
- ↑ Bacterial squalene cyclases can accept oxidosqualene as their substrates, but oxidosqualene usually does not exist in bacteria
- ↑ A trace amount of phytosterols comes from lanosterol. Ohyama K, Suzuki M, Kikuchi J, Saito K, Muranaka T (2009) Dual biosynthetic pathways to phytosterol via cycloartenol and lanosterol in Arabidopsis Proc Natl Acad Sci USA 106(3):725-730
- ↑ The most accessible enzyme among oxidosqualene cyclases.
Ref. Corey EJ, Russey WE, Ortiz-de-Montellano PR (1966) 2,3-Oxidosqualene, an intermediate in the biological synthesis of sterols from squalene J Am Chem Soc 88:4750-1 - ↑ The rings of protosteryl cation are chair-boat-chair configuration. The C-17 chain is β-configuration, not α.
Ref. Corey EJ, Virgil SC (1991) An experimental demonstration of the stereochemistry of enzymic cyclization of 2,3-oxidosqualene to the protosterol system, forerunner of lanosterol and cholesterol. J Am Chem Soc 113:4025-6 - ↑ The rings of dammarenyl cation are all-chair configuration. The C-17 chain is β-configuration.
Ref. Xiong Q, Rocco F, Wilson WK, Xu R, Ceruti M, Matsuda SPT (2005) Structure and reactivity of the dammarenyl cation: configuration transmission in triterpene synthesis. J Org. Chem. 70:5362-75
Useful Reviews:
- Xu R, Fazio GC, Matsuda SPT (2004) On the origins of triterpenoid skeletal diversity. Phytochemstry 65:261-291 PMID 14751299
BACTERIA | |
squalene | |
squalene-hopene cyclase[1] | |
17α-deoxydammarenyl cation[2] | |
D-ring expansion[3] | |
hopene |
|
Examples. |
Design of Tri-terpene ID numbers ID番号の設計
12-DIGIT
T | P | 3 | x | y | y | r | h | g | n | c | c |
- x ... species information
Symbol at x | Kingdom | Phyla | Examples |
---|---|---|---|
I | Animalia | Arthropoda (Insects, crabs) | ecdysteroids |
V | Chordate (Vertebrates) | sex steroids, corticosteroids, anabolic steroids | |
O | Others | marine steroids | |
P | Plantae | Phytosterols | lanosterols, cholesterols, brassinolides |
S | Saponins | saponins | |
F | Fungi | ergosterols | ergosterols |
B | Bacteria | bacterial sterols | hopanoids |
- y ... backbone structure (母核構造)
- r ... number of major rings (環構造数)
Click above categories to see details.
- h ... hydroxylation pattern (水酸基数)
Click above categories to see details.
- g ... glycosylation pattern(糖修飾パターン)
Click above categories to see details.
- n ... number of sugars (修飾糖数)
Click above categories to see details.
- c ... serial number (通し番号)
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